Actually, I only sleep about 5 hrs a night. Used to be about 3-4 hours but I'm getting older now.
Doing two seperate installs of Gallery would require two licenses and some changing of the code (others have inquired about into the past but I'm not familiar with any actual implementions of somebody doing it in on a live site). It'd be easier to just create seperate categories. Depending upon the type of user experience you want you could create two categories, one for music and one for video, make them 'inactive' so that they don't show up in the master category listing, and then link directly to the categories so you'd end up with one "Music Gallery" and one "Image Gallery". Bear in mind though that the templates would be still the same between them so they would both have the same look & feel unless you did some major modifications to the templates.